Java review note

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Abstraction:

• Big programs are built out of small methods.
• Methods can be individually developed,tested and reused.
• User of method does not need to know how it works.

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Good programming style

• Rule 1: Use good(meaningful) names

  String a1;
  int a2;
  double b;         // BAD!!
  String firstName; // GOOD String lastName; // GOOD int temperature; // GOOD

• Rule 2: Use indentation

  public static void main (String[] arguments) { int x = 5;
  x = x * x;
  if (x > 20) {
  System.out.println(x + “ is greater than 20.”); }
  double y = 3.4; }

Ctrl-shift-F to auto-format the file

• Rule 3:Use whitespaces
  Put whitespaces in complex expressions:

  // BAD!!
  double cel=fahr*42.0/(13.0-7.0);
  // GOOD
  double cel = fahr * 42.0 / (13.0 - 7.0);

• Rule 4:Do not duplicate tests

  if (basePay < 8.0) { ...
  } else if (hours > 60) { ...
  } else if (basePay >= 8.0 && hours <= 60){ ...
  }

—————–BAD—————–

Something about loop

• break: terminates a for a while loop
  

• continue: skips the current iteration of a loop and preceeds directly to the next iteration.
  

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